Tagan TG480-u01

[bokkie]

Tagan TG480-u01 PSU worked fine for years in my wife's pc.
Her videocard had problems so i baked it, worked great for months.
Problems came back, backed it again and fine for months again ...
now i baked it for the third time ....
PC wouldn't start.
measured the videocard's resistance between ground and 12v (pci-e 6pin)
low ohm (?150? can't remember)
so last bake wasn't that good of an idea

anyhow...

psu 5vsb is present (purple wire), 5v switch is present (green wire) and pulls low on power-on
but nothing happens, no fans nothing
you can hear a very faint ticking

pulled the psu apart, nothing to see, even all the caps look pristine (the ones i measured esr are fine)

desoldered both heatsinks + diode's/transistors
only defect i could find till now is one of the 2 2sc3320 is blown (base-collector gives 150ohm both way's)

anything else i should check or should replace the 2sc3320 suffice ?

[bokkie]

Re: Tagan TG480-u01

found some bu508a, higher voltage lower amperage thou
put them in just for testing and running fine

anyone have an idea thou how to mod the fancontrolboard for higher speed ?

[domas]

Re: Tagan TG480-u01

can you take a picture of your board? both sides please

i have a spare one i am looking at now, and I see a resistor connected to a thermistor, try changing that one to one with lower value, it is marked as FR7 on my board.

My thermistor is reading 2.7Kohms in +20C ambient temp.. it got as low as 0.6-0.7Kohm as I heated it with a lighter if your does the same, you will know how resistance is related to temp and change components accordingly

[bokkie]

Re: Tagan TG480-u01

made a sort of diagram of the fan controller

left you can see the 3 fan headers and on top is the input going through 470 and 560 and so on

[bokkie]

Re: Tagan TG480-u01

weird, 5v and 3.3 are perfectly fine
on the 12v line, i only get 11v at no load, with a 1A fan it even drops to about 10.9v
this psu i so da*n crowded, hard to follow the rail.
does anyone have diagrams/schematics for this "topower" design?

[bokkie]

Re: Tagan TG480-u01

under load 12v is fine (12.14)
so working again

only the fan-mod resides, should be the 3.3k ohm i guess ?!

[Behemot]

Re: Tagan TG480-u01

You may try pot to find the right value